Event Driven Development

Transcript

1. Event Driven Development Christopher Riley ConFoo 2018 1

2. Introduction

3. Introduction • Event sourcing 2

4. Introduction • Event sourcing • Event Driven Architecture 2

5. Introduction • Event sourcing • Event Driven Architecture • Task

   Based UI 2

6. Introduction • Event sourcing • Event Driven Architecture • Task

   Based UI • Event storming 2

7. What is an event? 2

8. What is an event? • Something which has happened in

   the past 3

9. What is an event? • Something which has happened in

   the past • Relevant to a domain expert 3

10. What is an event? • Something which has happened in

    the past • Relevant to a domain expert • Not technical 3

11. What is an event? • Something which has happened in

    the past • Relevant to a domain expert • Not technical • Raised in response to an input 3

12. Task based UI

13. A CRUD UI 4

14. A Task Based UI 5

15. Everything a company does is part of a process 5

16. Why are task based UI’s helpful to event based systems?

    5

17. Event sourcing

18. A familiar model 6

19. Event sourcing example 7

20. What does an event sourced system actually look like? 7

21. Event sourcing architecture 8

22. Handling a command 9

23. Inside the model 10

24. Inside the model 11

25. Handling Events 12

26. Projections

27. Projections • Turn events into read models 13

28. Projections • Turn events into read models • Can be

    eventually consistent 13

29. Projections • Turn events into read models • Can be

    eventually consistent • Can be rebuilt 13

30. A projection 14

31. Process Managers

32. Process managers • Handle business logic around events 15

33. Process managers • Handle business logic around events • A

    state machine 15

34. Process managers • Handle business logic around events • A

    state machine • Keep track of failures 15

35. Process managers • Handle business logic around events • A

    state machine • Keep track of failures • Be careful with replays 15

36. A Process Manager 16

37. Event Driven Architecture

38. Event Driven Architecture 17

39. Cross System Process 18

40. Conclusions

41. Thanks • @giveupalready • https://github.com/carnage • https://carnage.github.io 19